1. Field of the Invention
This invention relates to semiconductor packages and methods of fabricating the same, and, more particularly, to a semiconductor package having a stator set formed by circuits and a method of fabricating the semiconductor package.
2. Description of Related Art
A circuit board, such as a main board or a mother board, has disposed thereon a plurality of electronic components, such as a central processing unit or a graphic card, and conductive circuits that are electrically connected to the electronic components. In operation, the electronic components generate heat. The electronic components will malfunction if the heat is not effectively dissipated to a region outside of an electronic product in which the circuit board is installed. The heat-dissipating capability plays a dominant role in modern electronic products that have various functions and operate at a high speed. The various functions and high operation speed mean that more and higher-leveled electronic components are integrated on the circuit board. As a result, more heat is generated by a modern electronic product, and how to dissipate the heat generated by the electronic components is becoming a serious issue in the art.
A heat-dissipating fan is installed on a main board or a mother board, to dissipate the heat generated by the electronic components and/or the electronic products. U.S. Pat. Nos. 6,799,282, 7,215,548, 7,286,357 and 7,568,517 disclose such a heat-dissipating fan.
A conventional heat-dissipating fan, as shown in FIG. 1A, is installed at a predetermined position on a circuit board, and comprises a printed circuit board 11, a housing 12 and an impeller 13. The housing 12 comprises a base 120, an axial tube 122, and a stator set 121 surrounding the axial tube 122. The impeller 13 comprises a hub 130, a magnet 131 installed on an inner side of the hub 130, a plurality of blades 132 surrounding an outer side of the hub 130, and a shaft 133 axially coupled to the hub 130 and axially installed in the axial tube 122. The printed circuit board 11 has at least one control chip 110 and a plurality of passive components 112 disposed thereon. The printed circuit board 11 is disposed on the base 120 of the housing 12. The control chip 110 controls the rotation of the impeller 13, and the rotating impeller 13 drives airflow.
The control chip 110 of the heat-dissipating fan shown in FIG. 1A is also a heat-generating source, and will malfunction if the heat cannot be dissipated effectively. Once the control chip 110 malfunctions, the heat generated by the electronic components installed on the main board of the electronic product cannot be dissipated effectively, and the electronic product is likely to operate abnormally or even be damaged. The control chip 110 is installed exactly in a gap between the base 120 of the housing 12 and the impeller 13. The gap is so small that the heat generated by the control chip 110 cannot be dissipated effectively. As a result, the control chip 110 is overheated and damaged eventually. Though being very cheap as compared to key components of the electronic product, the heat-dissipating fan, if malfunctioning, will affect the normal operation of the key components.
Besides, the installation of the control chip 110 affects the size of the gap between the hub 130 of the impeller 13 and the base 120 of the housing 12, and the thickness of the control chip 110 amounts to the height of the gap, which is adversely to the reduction of the overall height of the heat-dissipating fan. The control chip 110 occupies the precious area of the printed circuit board 11. If the printed circuit board 11 cannot be reduced any further, the blades 132 have to have their sizes reduced. However, the airflow of the blades 132 with reduced sizes is reduced accordingly. As a result, the heat-dissipating effect is greatly impacted.
In order to solve the above problem, U.S. Pat. No. 7,345,884 discloses an improved heat-dissipating fan. As shown in FIG. 1B, the heat-dissipating fan of U.S. Pat. No. 7,345,884 differs from the heat-dissipating fan shown in FIG. 1A in that a printed circuit board 11′ of the heat-dissipating fan of U.S. Pat. No. 7,345,884 has an extension portion 11a extending externally for a control chip 110′ to be disposed thereon, such that the control chip 110′ is disposed in a gap between a base 120′ of a housing 12′ and a hub 130′ of an impeller 13′ or has a portion exposed from the gap. Therefore, the airflow driven by the impeller 13′ can dissipate the heat generated by the control chip 110′.
However, the extension portion 11a of the printed circuit board 11′ interferes the airflow generated by the impeller 13′. The airflow, if interfered, generates noises and affects the quality of an electronic product in which the heat-dissipating fan is installed. Besides, since the extension portion 11a extends externally, blades 132′ have to be away from the control chip 110′ at a predetermined interval, which is also adversely to the reduction of the overall height of the heat-dissipating fan. Therefore, the electronic product cannot meet the compact-size and low-profile requirements.
Moreover, since in the heat-dissipating fan the printed circuit board 11′ still has to be installed between the hub 130′ of the impeller 13′ and the base 120′ of the housing 12′, the height of the heat-dissipating fan is thus affected by the thickness of the printed circuit board 11′ and cannot be reduced any further.